Vertical Development Device Layout for Toner-Scattering Control

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Solution Overview

Problem

Existing development devices in image forming apparatuses face challenges in reducing size while preventing toner scattering, especially in color-printing models with multiple development devices, as conventional configurations lead to toner scattering and require additional components to manage this issue.

Innovation Solution

A development device with a first and second conveyance chamber arranged in the up-down direction, utilizing first and second stirring conveyance members to convey and stir developer, and a regulation blade to control developer layer thickness, which prevents toner scattering by collecting developer in the second conveyance chamber below the development roller.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the first and second conveyance chambers are arranged in the horizontal direction, then the device complexity is reduced, but the size of the development device increases in the horizontal direction

Engineering Contradiction:
Improvearrangement structureVSAvoidhorizontal size of development device
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent transitions from horizontal arrangement to vertical arrangement of the first and second conveyance chambers. This dimensional change allows the chambers to be stacked in the vertical direction, thereby reducing the horizontal footprint of the development device while maintaining all necessary functional components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If the conveyance chambers are arranged in the up-down direction to reduce horizontal size, then the horizontal area is reduced, but toner scattering occurs outside the development device

Engineering Contradiction:
Improvehorizontal size of development deviceVSAvoidtoner scattering
Core Design Contradiction:
Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent positions the development roller in the vertical direction between the first and second conveyance chambers, creating a vertical stacking arrangement. This spatial reconfiguration contains the developer flow within the vertical axis, preventing toner scattering horizontally while maintaining compact dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The development roller acts as an intermediary component positioned vertically between the two conveyance chambers. It mediates the developer transfer from the chambers while containing the developer within the vertical space, preventing horizontal scattering of toner.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If additional components are added to prevent toner scattering, then the harmful factors are reduced, but the device complexity increases

Engineering Contradiction:
Improvetoner scatteringVSAvoidnumber of components
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The development roller serves multiple functions: it conveys developer from the conveyance chambers, forms the developer layer on its surface, and prevents toner scattering by containing the developer within the vertical arrangement. This multi-functionality eliminates the need for separate scattering prevention components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The vertical arrangement of conveyance chambers and development roller creates a self-contained system where the developer is naturally contained within the vertical space. The gravity-assisted developer flow and the compact vertical configuration work together to prevent scattering without requiring additional containment structures.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration effectively prevents toner scattering, reduces the size of the development device and image forming apparatus, and eliminates the need for additional components to manage scattering, allowing closer arrangement of photosensitive drums and development devices.

Implementation Method 1

The first stirring conveyance member is rotatably supported in the first conveyance chamber and conveys, while stirring, the developer in the first conveyance chamber in the first direction

Methodology Applied
Scientific EffectConveyance by rotating member:

Implementation Method 2

The second stirring conveyance member is rotatably supported in the second conveyance chamber parallel to the first stirring conveyance member and conveys, while stirring, the developer in the second conveyance chamber in the second direction opposite to the first direction

Methodology Applied
Scientific EffectConveyance by rotating member:

Implementation Method 3

The developer carrying member is rotatably supported on the development container and carries on its surface the developer in the second conveyance chamber

Methodology Applied
Scientific EffectConveyance by rotating member:

Implementation Method 4

The regulation blade is arranged opposite the developer carrying member and regulates the layer thickness of the developer on the developer carrying member

Methodology Applied
Scientific EffectMechanical regulation:

Data Source

PatentEP4632492A1Development device and image forming apparatus provided therewith
Publication Date: 2025.10.15 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4632492A1 patent drawingFigure 1
  • EP4632492A1 patent drawingFigure 2~3
  • EP4632492A1 patent drawingFigure 4

AI summary

A development device (3a to 3d) includes a development container (22) having a first conveyance chamber (22b) and a second conveyance chamber (22c) above it, first and second stirring conveyance members (43, 44) that stir developer in the first and second conveyance chambers (22b, 22c) and convey it in the opposite directions, a developer carrying member (20) that carries on its surface the developer in the second conveyance chamber (22c), and a regulation blade (27) that regulates the layer thickness of the developer on the developer carrying member (20). Feeding of the developer to the developer carrying member (20) and collection of the developer from the developer carrying member (20) are performed in the second conveyance chamber (22c). A horizontal straight line L1 through the center of the rotation shaft (44b) of the second stirring conveyance member (44) is above a horizontal straight line L2 through the center of the rotation of the developer carrying member (20) and the straight line L2 is above a horizontal straight line L3 through the center of the rotation shaft (43b) of the first stirring conveyance member (43).